Metal molding and casting appliance.



I, A. C. ATKINSON.

METAL MOLDING AND CASTING APPLIANCE.

APPLICATION FILED OCT. 14 I916.

Patented; May 8, 1917.

1,225,2@&

ATTORNEY UNTTED STATE PATENT @FFTCE.

ALFRED CHARLES ATKINSON, 0F KELBURN, WELLINGTON, NEW ZEALAND.

METAL MOLDING AND CASTING APPLIANCE.

Application filed October 14, 1916.

To all whom it may concern:

Be it known that I, ALFRED CHAnLns An- KINSON, subject of the King ofGreat Brltain, residing at Kelburn, Wellington, New Zealand, haveinvented a new and useful Metal Molding and Casting Appliance; and I dohereby declare the following to be a full, clear, and exact descriptionof the same.

This invention relates particularly to the appliances employed indentistry for the molding and casting of light metal parts, but it isapplicable also to the moldlng and casting of any other metal work, suchas jewelers work. I

The invention relates to improvements in the means employed in the wellknown system of molding and casting such articles in which a pattern ismade of a fusible material having a low melting point and which patternis then placed within amold box and surrounded by an investment material(generally a plaster of Paris composition) and the whole submitted toheat so as to melt and burn out the pattern, leaving a mold in theinvestment of corresponding shape. The metal of which the casting is tobe formed is then melted and forced into the mold by artificialpressure, while the mold is still hot, through suitable runners whichalso allow of the draining away of the pattern material on the initialheating of the mold. The means provided are, however, applicable to anyother system in, which provision has to be made for the forcing of ametal having a high melting point into a mold formed in an investmentmaterial.

The invention consists in means designed to provide for the mold boxbeing held in position and the pattern positioned within it, while theinvestment material is placed within the box, such means being of such anature as to provide for the necessary metal melting chamber in the topend of the mold and for the runner or runners extending therefrom intothe mold.

In fully describing the invention, reference will be made to theaccompanying sheet of drawings, in which Figure l is a plan, and

Fig. 2 a sectional elevation of the complete mold ready for casting.

Fig. 3 is an elevation.

Fig. 4 is a plan, and

Fig. 5 is a sectional elevation of the means comprising this inventionarranged in the Specification of Letters Patent.

Patented May 8, 191?.

Serial No. 125,592.

The means employed consist of the ordinary metallic casing or moldingbox A of any desired size and cross sectional shape and having its topand bottom ends open. The casing in this invention is formed with agroove or recesses A around its inner surface near the bottom end intowhich the investment material with which the casing is filled will enterso as to form a key to hold such material from movement in the casingwhen it has set.

The upper end of the casing in this invention also is provided with acover B adapted to fit over it and having lugs B depending from itsunder surface which lugs engage with the inside of the casing. They arealso formed with apertures into which the investment will pass so as tohold the cover firmly on the casing. The cover is formed with a centralcircular aperture C and surrounding such aperture on the top side, is arim or collar D of any approved height.

A base plate E is provided for support ing the molding apparatus duringthe molding operation, such base plate being of circular form and havingan upwardly projecting flange E around its outer edge and a well ordepression F on its center. Fitting within the flange of the base plateis a disk G also formed with a flange G upon its edge and projectingupwardly therefrom. At the center of the disk is an upwardly projectingcone H having a central bore J extending down from its apex through thedisk, which on its underside may be hollowed out approximately inconformity with the cone, as shown in Fig. 5 and for a purpose that willbe hereinafter described. The cone is provided with a number of ribs Hextending radially down its surface, as indicated in Fig. 6 which is aplan view of the disk and cone. The diameter of the base of the cone ismade greater than the diameter of the aperture C of the casing cover. F

In assembling the parts for the molding operation the disk G is placedin position on the base plate the well or depression F of which haspreviously been filled with a suitable wax material. The cover B of thecasing is then placed upon the cone H so that the cone passes up throughthe central aperture C and the edge of the rim D rests upon the cone.The pattern represented by K in the drawings, which has previously hadthe ordinary sprue or runner pin M attached to it by wax or otheryielding material, is then positioned above the cover by passing the endof the sprue pin prevoiusly warmed down through the bore J of the coneand into the wax in the base plate beneath, which will then serve tosupport it and the pattern. The undercutting of the disk beneath thecone will allow of the sprue pin being passed down at any desired angleto the vertical and held by the wax, in order to adjust the position ofthe pattern above the casing cover.

The casing is then placed in position over the cover and by reason ofthe engagemem of the rim of the cover aperture with the cone, suchcasing and cover may be tilted to any side in order to position thepattern centrally within the casing. The investment material is thenpoured in to fill up the casing and when it has set the casing islifted, thereby drawing the sprue pin from its wax support and leaving adepression in the end of the investment corresponding in shape with thecone H and having grooves extending down the surface of such depressioncorresponding with the ribs H. The sprue pin is then withdrawn leavingthe runner hole formed thereby extending from the bottom of thedepression into the mold as shown in Fig. 2.

The casting is then carried out in the usual way the mold being heatedand the metal placed within the depression in the top end and melted byany approved means and then forced into the mold through the runner bysteam or compressed air obtained by any of the known methods. Thegrooves of gases and air from the mold instead of formed by the ribs Hprovide for the escape having to pass up through the mass of the metalin the depression.

When it is desired to mold and cast a number of articles at the sametime, the disk may be varied in shape as shown in Fig. 7. In such a casethe cone is formed with a number of apertures 00 in its surface throughwhich the several sprue pins y of the different patterns are passed soas to allow for their proper disposition within the casing in relationto one another and to provide the requisite runners for such molds.

1. In means for the purposes herein described the combination with amold casing, of a cover adapted to fit over one end thereof and formedwith a central circular aperture and with a rim surrounding suchaperture on its outersurface, substantially as herein specified.

2. Means for the purposes herein described comprising the combinationwith the mold casing, of a cover therefor formed with a central circularaperture and with a rim on its outside surrounding the edge of suchaperture, and a disk plate having a cone shaped center upon which theaperture in the casing cover is adapted to pass and rest, such conebeing formed with an aperture extending vertically through it,substantially as herein specified.

In the means for the purposes herein described, the combination with themold casing, of a cover therefor formed with a central circularaperture, :1. disk having a central upwardly projecting cone upon whichthe aperture in the casing cover is adapted to pass and rest and formedwith an aperture extending vertically through the cone, and a base plateon which the disk rests formed with a depression beneath the cone of thedisk.

4. Means for the purposes herein described comprising the combinationwith the mold casing, of a cover therefor formed with a central circularaperture and with a rim on its outside surrounding the edge of suchaperture, and a disk plate having a cone shaped center upon which theaperture in the casing cover is adapted to pass and rest, such conebeing formed with an aperture extending vertically through it, andformed with a number of slight ribs extending radially down its surface,substantially as and for the purposes specified.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

ALFRED CHARLES ATKINSON.

\Vitnesses IV. ALEXANDER,

M. E. BROWN.

Copies of this patent may be obtained for fivecents each, by addressingthe Commissioner of ratents. Washington, D. G.

